低多样性的肠道菌群紊乱在不同的疾病背景下会呈现不同的形式。在本研究中，我们使用了重测序和气相色谱-质谱（GC-MS）技术，对克雷韦尔(克罗米杜) 困难患病者的代谢组和微生物组进行了对比，并定义了克雷韦尔(克罗米杜)困难感染对肠道菌群紊乱的附加效应。研究队列包括138例混合病例的癌症患者、43例炎症性肠病患者和45例健康对照个体。其中，三个已知的肠道菌群类型在对照组中被鉴定出，而其他组则出现了额外的大肠杆菌驱动的肠道菌群类型。所有组的细菌多样性都明显低于健康对照组，而癌症患者的细菌种类丰富度最高。56种细菌物种的丰度水平能够区分腹泻患者组与对照组。其中，52种物种在所有腹泻患者组中呈现低表达，而4种物种（拟杆菌、大肠杆菌、肺炎克雷伯菌和鼠肠球菌）呈现高表达。丙酸盐和丁酸盐的相对丰度在炎症性肠病和克雷韦尔困难感染患者的粪便样本中明显低于对照样本。异丁酸盐、丙酸盐和丁酸盐的浓度在癌症、炎症性肠病和克雷韦尔困难感染样本中分别较低。甘氨酸和缬氨酸氨基酸在腹泻患者中呈现高表达。我们的数据表明，外部和内部因素推动了具有相似低多样性紊乱特征的菌群组合。而腹泻相关的低多样性菌群紊乱可能是系统性癌症治疗的结果，而中度至重度炎症性肠病的情况下也观察到了类似的表型，并且在这两种情况下，困难感染的发生加剧了菌群紊乱的程度。版权所有©2023 Kulecka, Zeber-Lubecka, Bałabas, Czarnowski, Bagińska, Głowienka, Kluska, Piątkowska, Dąbrowska, Waker, Mikula and Ostrowski。

Low diversity gut dysbiosis can take different forms depending on the disease context. In this study, we used shotgun metagenomic sequencing and gas chromatography-mass spectrometry (GC-MS) to compared the metagenomic and metabolomic profiles of Clostridioides (Clostridium) difficile diarrheal cancer and inflammatory bowel disease (IBD) patients and defined the additive effect of C. difficile infection (CDI) on intestinal dysbiosis.The study cohort consisted of 138 case-mix cancer patients, 43 IBD patients, and 45 healthy control individuals. Thirty-three patients were also infected with C. difficile. In the control group, three well-known enterotypes were identified, while the other groups presented with an additional Escherichia-driven enterotype. Bacterial diversity was significantly lower in all groups than in healthy controls, while the highest level of bacterial species richness was observed in cancer patients. Fifty-six bacterial species had abundance levels that differentiated diarrheal patient groups from the control group. Of these species, 52 and 4 (Bacteroides fragilis, Escherichia coli, Klebsiella pneumoniae, and Ruminococcus gnavus) were under-represented and over-represented, respectively, in all diarrheal patient groups. The relative abundances of propionate and butyrate were significantly lower in fecal samples from IBD and CDI patients than in control samples. Isobutyrate, propanate, and butyrate concentrations were lower in cancer, IBD, and CDI samples, respectively. Glycine and valine amino acids were over- represented in diarrheal patients.Our data indicate that different external and internal factors drive comparable profiles of low diversity dysbiosis. While diarrheal-related low diversity dysbiosis may be a consequence of systemic cancer therapy, a similar phenotype is observed in cases of moderate to severe IBD, and in both cases, dysbiosis is exacerbated by incidence of CDI.Copyright © 2023 Kulecka, Zeber-Lubecka, Bałabas, Czarnowski, Bagińska, Głowienka, Kluska, Piątkowska, Dąbrowska, Waker, Mikula and Ostrowski.